Abstract

In this paper, we consider inverse problems of finding the time-dependent source function for the population model with population density nonlocal boundary conditions and an integral over-determination measurement. These problems arise in mathematical biology and have never been investigated in the literature in the forms proposed, although related studies do exist. The unique solvability of the inverse problems are rigorously proved using generalized Fourier series and the theory of Volterra integral equations. Continuous dependence on smooth input data also holds but, as in reality noisy errors are random and non-smooth, the inverse problems are still practically ill-posed. The degree of ill-posedness is characterised by the numerical differentiation of a noisy function. In the numerical process, the boundary element method together with either a smoothing spline regularization or the first-order Tikhonov regularization are employed with various choices of regularization parameter. One is based on the discrepancy principle and another one is the generalized cross-validation criterion. Numerical results for some benchmark test examples are presented and discussed in order to illustrate the accuracy and stability of the numerical inversion.

Highlights

  • Time-dependent coefficient identification problems for parabolic equations have been the point of interest for many studies, including the excellent monograph [11] and the book [16]

  • The boundary conditions are usually of Dirichlet, Neumann or Robin type but, more recently, nonlocal boundary conditions arising in population age models have been considered, [5, 6, 7]

  • We have considered the inverse problem of finding the time-dependent coefficient P (t) in the IP1 by using the boundary element method (BEM) together with the smoothing spline regularization technique

Read more

Summary

Introduction

Time-dependent coefficient identification problems for parabolic equations have been the point of interest for many studies, including the excellent monograph [11] and the book [16]. In comparison with previous related studies, [4, 6, 7, 9, 10, 12], in the current investigation, the birth rate in the population age model [15] is an arbitrary constant and the boundary conditions and the additional observation are both nonlocal and integral, respectively.

Mathematical formulation
Mathematical analysis
The auxiliary spectral problem
BEM for IP1
BEM for IP2
Numerical results and discussion
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call